Polycystic kidney disease

Also called PKD, ADPKD

An inherited condition in which cysts gradually replace the kidneys. The commonest inherited cause of kidney failure, and one drug now slows it.

What it is

An inherited condition in which fluid-filled cysts develop in the kidneys, gradually enlarging them and destroying working tissue.

The adult form, autosomal dominant PKD, is the commonest inherited kidney disease, affecting around 1 in 1,000 people. Each child of an affected parent has a one in two chance. It usually causes symptoms from the thirties or forties, and around half of people reach kidney failure by around 60, needing dialysis or transplant.

A rarer recessive form presents in infancy and is much more severe.

Two things have changed. **Tolvaptan** is a drug that slows cyst growth and the decline in kidney function in people with rapidly progressing disease, and it is available on the NHS through specialist centres. Not everybody is eligible, but everybody should be assessed.

And blood pressure control matters more here than almost anywhere: it is the single most effective thing available to slow progression, and targets are tighter than for the general population.

It is not only a kidney condition. Cysts occur in the liver, and there is an increased risk of brain aneurysms and subarachnoid haemorrhage, particularly where there is a family history of one, which is a reason for screening in some families.

Signs you might notice

Often nothing for decades.

High blood pressure, frequently the first sign, sometimes in young adulthood.

Pain in the back or sides, or a feeling of fullness in the abdomen.

Blood in the urine, from a bleed into a cyst.

Repeated urinary or kidney infections.

Kidney stones.

Later, symptoms of chronic kidney disease: fatigue, itching, nausea, swelling.

999: sudden severe headache reaching maximum intensity within a minute, which may be a ruptured aneurysm.

Urgent: fever with loin pain, which may be an infected cyst and needs different antibiotics from an ordinary infection; or sudden severe flank pain.

How it can affect day-to-day life

Knowing about it decades before it causes problems is a particular burden, and so is watching a parent go through dialysis while knowing the same is likely.

The genetic implications reach the whole family, including decisions about testing children, which is usually deferred until adulthood, and about having children.

Pain from enlarged kidneys is real, often chronic, and frequently under-treated because it does not show on tests.

Anti-inflammatory painkillers should generally be avoided because they damage kidneys, which limits options and needs a proper pain plan.

Drinking plenty of water, enough to keep urine pale, may modestly slow cyst growth and is a simple thing within a person's control.

Living donor transplantation gives the best outcomes and is worth discussing early, before dialysis, rather than late.

Supporting someone well

Control blood pressure aggressively; it is the most effective intervention available.

Ask about tolvaptan and about referral to a specialist PKD service for assessment of eligibility.

Drink enough water to keep urine pale, unless advised otherwise.

Avoid anti-inflammatory painkillers, and ask for a proper pain plan instead.

Ask about screening for brain aneurysms where there is a family history of one or of sudden death.

Get fever with loin pain assessed promptly; infected cysts need specific antibiotics.

Ask about family testing and genetic counselling, including before pregnancy.

Ask about pre-emptive transplantation and living donation early, not when dialysis is imminent.

Keep kidney function monitored regularly.

Where to get help

A GP practice for referral to nephrology; a specialist PKD service for tolvaptan assessment.

999 for sudden severe headache.

PKD Charity run a helpline and are the specialist charity.

Kidney Care UK for support, benefits and practical help.